Press for forming tubes, &amp;c.



No. 847,685. PATENTED MAR. 19, 1907 W. ASTFALOK. PRESS FOR FORMING TUBES, 6w.

APPLICATION FILED 00131, 1966,

V KW E Z UNITED STATES PATENT OFFICE.

WILAND ASTFALOK, OF TEGEL, NEAR BERLIN, GERMANY.

PRESS FOR FORMING TUBES, &c.

Specification of Letters Patent.

Patented March 19, 1907.

Application filed October 1. 1906. Serial No. 336.966.

This invention relates to a press for forming tubes and tubular hollow bodies from a solid metal block or blank, which is punched in one operation by means of a mandrel driven into the matrix-hole and then pressed, by means of a press-ram, between the mandrel and the matrix-wall.

Hitherto a cylindrical mandrel was used, which when punching the metal block comes in contact with the incandescent mass in its entire length, squeezes through the metallic mass, assumes the temperature of the same, and is thus deprived of its tenacity. Moreover. when the said mandrel passes through the incandescent mass its surface undergoes changes of shape, and when it finally acts as a mandrel it is no longer resistabl'e enough and is sometimes even throttled. At any rate, its upper surface is so all'ected that it no Longer has the accurate shape anddimensions which it'ought to have.

According to the present invention this drel has also theessential advantage that it maintains a greater degree of rigidity, because it does not get excessively heated when punching the block, and it cannot, therefore, yield in a lateral direction, which would lead to the formation of irregular-walled tubes. l Power is always saved when using the new mandrel, for when punchingonly' the frictional resistance between the metal block, on the one hand, and the press-cylinder and the 1 mandrel-head, on the other hand, is to be 5 taken into account, while with the ordinary i mandrel the resistance on the entire length of drawback is overcome by making the mandrel thicker at its front end,,whereupon this thicker head is loosely mounted on the mandrel-rod, and after punching the metal block thehead is broken oil' by the tube which is being formed. then come in direct contact with the metal the mandrel considered. 1 The accompanying drawing shows diagrammatically the respective part of a tubeforming press in three forms of construction. Figures 14 are longitudinal sections through the press-cylinder in different working positions of the mandrel and the pressram. Figs. 5 and 6 are also longitudinal sections through the press-cylinder and show independently-operated mandrel and pressram. Fig. 7 is a side elevation of another form of construction of the mandrel.

The press-cylinder a is open atone end and has a matrix-hole b at the other end. A press-ram c and a mandrel d are arranged in punching the metal is also to be lrcnt of the presscylinder a and adapted to.

reciprocate therein. In order that the mandrel can get mto the operative position for' the pressing operation, the mandrel d must Q'iirst be forced through the solid metal block or blank 0 inserted in the cylinder a.

The mam'lrel-shank does not when punching and cannot, therefore, he in the same incandescent state as the mass;

i\loreover, owing to the obviation of 1 According to this invention there is mounted on the mandrel d at the front end a head-piece j, which has a somewhat larger diameter than the mandrel. In order that the head-piece f may remain on the mandrel (l and not be easily knocked oil, the man drel is provided with a pin 9, according to Fig. 4, and the head-piece is provided with a central hole h, wherein the pin 9 accurately duct formed, as in the event of a higher specific pressure the metal block is more strongly compressed and a more homogeneous tube passes out ol the press. Tubes ol less diameter may also be pressed, because the mandrel is not heated in the mass as hitherto. Further, only the -mandrelh'ead need be replaced if it has been changed through the repeated working process. while hitherto the whole mandrel had to be re placed or shortened. Finally, the new mantits.

If the press-ram c is moved forward with the mandrel d, a portion of the metal then enters the matrix-hole b in the form of a plug i, Figs. 2 and 3. When the metal block e is completely punched and the press-ram c bears against the metallic mass, Fig. 3, the pressing operation begins. By the pressure of the ram 0 the plug '1' and then the headpiece f of the mandrel (I will be pressed out through the matrix-hole b,and the tube 1c, Fig. 4, is formed about the mandrel d, enterconnected to the press-ram c.

ing the matrix-hole b. The head-piece f is thus stripped off the mandrel d by the following tube 7c.

in Figs. 1 and 4 the mandrel d is rigidly The mandrel (2 may, however, also be movably arranged in the press-ram c and operated independently thereof, as assumed in Figs. 5 and 6.

Fig. 7 represents a mandrel d the headpiece f 'of which is offset. The working edge m has a diameter corresponding to the inside width of the matrix-hole.

What I claim as my invention, and desire to secure by United States Letters Patent, 1s

1. An improved press for forming tubes and tubular hollow bodies from a solid metal block, comprising a press-cylinder terminating in a matrix, a mandrel and a press-ram,

the said mandrel being provided with a headpiece projecting above the mandrel and loosely connected therewith substantially as described and shown in the drawing. I

2. An improved press for forming tubes and tubular hollow bodies from a solid metal block, comprlslng a press-cylinder termmating in a matrix, a mandrel provided with a 1 loosely-mounted head-piece and a press-ram,

the said head-piece of the mandrel having a I working edge projecting above the mandrel,

substantially as described and shown in the 1 drawing. l '3. An improved press for forming tubes i and tubular hollow bodies from a solid metal block, comprising a press-cylinder terminating in a matrix, a mandrel provided with a 1 loosely-mounted head-piece and a press-ram, the said head-piece of the mandrel having a working edge projecting above the mandrel Q and a diameter equal to the inside width of the matrix, substantially as described and 1 shown in the drawing. '4 4. In a press 'for forming tubes and tubular bodies, a mandrel provided with a performing-head loosely connected thereto. 5. In a press for forming tubes and tubular bodies, a mandrel provided with a perforating-head of greater diameter'than the mandrel and adapted to be stripped off during the formation of a tube.

The foregoing specification signed, at Berlin, Germany, this 19th day of September, 1906.

WILAN I) ASIFALCK.

I11 presence of- WoLDEMAR HAUP'r, HENRY HAsPEn. 

